--- guestbook.module	2008-08-13 15:26:32.000000000 -0700
+++ guestbook.module.modified	2009-04-07 19:11:15.000000000 -0700
@@ -320,7 +320,8 @@ function guestbook_page($uid = 0, $op = 
 
   // Set last visited time for own guestbook
   if ($uid > 0 && $user->uid == $uid) {
-    user_save($user, array('guestbook_visited' => time()));
+    $account = user_load(array('uid' => $user->uid));
+    user_save($account, array('guestbook_visited' => time()));
   }
 
   // Delete or comment an entry